Switching device



June 2, 1942. C. E. GARY swITcHING DEVICE Filed `Aug. 17, 1938 Hyg.

INVENTOR WITNESSES: @n/f MM Patented June 2, 1942 SWITCHING DEVICE Clarence E. Gary, Forest Hills, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 17, 1938, Serial No. 225,357

(Cl. 20D-5) 13 Claims.

This invention relates to a push button type switch for controlling one or more circuits, and is directed particularly to a mechanical interlock between two push buttons whereby the push buttons selectively and individually are held in a position to indicate the position of the contacts of the switch.

One object of my invention is to provide a simple mechanical interlocking arrangement between a pair oi push buttons that are to control the opening or the closing oi either oi two circuits, so that the push buttons shall be selectively held in a depressed position to indicate which associated circuit is closed.

Another object of the invention is to provide a simple construction and assembly that shall be relatively inexpensive to manufacture, and that shall have a minimum number oi parts of simple design in order to provide a mechanism that shall be satisfactory and effective in its operation, as well as inexpensive to manufacture and assemble.

Another object of the invention is to provide a push-button latching unit which may be supplied as a separate unit to convert a standard spring-biased push-button unit into an interlocked two-button device.

A push-button controller, with a mechanical interlock between the push-button, that is constructed in accordance with the principle of my invention, comprises, briefly, a movable switch contact that is manually operable by one push button, to engage either of two sets of members to close either of two associated electric circuits. In its raised position, the switch contact closes one circuit, and its button is in raised position. When the button is in depressed position, the switch contact opens the rst circuit and may close another circuit.

A pivoted latch is provided and is so disposed and constructed as to engage and latch the contact operating button when it is depressed to a position to close one circuit. A second button serves merely as a releasing device for the latch, to permit the first button to be released from its depressed position to move to its raised position, while the second button in turn becomes latched in its depressed position by the pivoted latching member.

The first push button, in moving to its initial raised position, cooperates with the latch member to serve as a stop for the latch member and to hold the latch member in effective position to latch the second button, so long as the first button remains in its raised position. Each button thus serves as a release button to control the latch to release the other or operated button. At the same time, the release button places itself in a position where it will be latched by the latching member, while the operated button, now being released, serves to hold the latch in effective position to hold the release button in operated or depressed position.

A push-button control switch provided with an interlock according to the principles of my invention is shown in the accompanying drawing, in which:

Figure l is a side elevational view of the pushbutton assembly in an enclosing box with the box in section;

Fig. 2 is a schematic view illustrating the disposition oi the latching member between the two push buttons to be controlled thereby, the portion of one button assembly being removed to show the latch clearly;

Fig. 3 is a front elevational view of the interlock control button and latch of Fig. 2 in its frame;

Fig. 4 is a plan view oi the frame of Fig. 3;

Fig. 5 is a front view of the frame of Fig. 4, related to the view in Fig. 5, and corresponding to the view in Fig. 3 with the latch and the operating button removed;

Fig. 6 is a side elevational view of the switch unit assembly of Fig. 1; and

Fig. '7 is a sectional view of the unit of Fig. 6.

As shown in the drawing, a push-button controller l comprises a molded insulating assembly unit support il, and four stationary contact members l2 to i5, inclusive, for two circuits that are to be completed by a movable contact member i6 operable by a push button I1, which is normally spring biased to its outer position by a biasing spring I8. A pivoted latch I9 is mounted upon an adjacent frame 20 to engage the pushbutton l1. A second push-button 2l, normally spring biased to its upper position by a biasing spring 22, is supported on the frame 20, and cooperates with the latch I9 to release the rst push-button H when the second push-button 2l is depressed to its lower position. Thereupon, the latch engages the second button 2l and holds it in a depressed position until the latch may be later released by the rst push-button I1.

The push-button I'.' is thus the switch operator for both circuits, and the push-button 2| serves as a latch operator to release the switch button I1 in one position. The latch button 2| thus serves, also, to indicate by its position which circuit is closed or open.

Thus, each button, when it is depressed to release the other button, becomes engaged by an element of the latch and is held in depressed position by that element of the latch. In the meantime, the other button is released and is permitted to move to its extreme outer position under the influence of its associated biasing spring.

The insulating support II`for the switch contacts is made up of two duplicate sections and 24 of molded material, upon which are mounted the respective stationary contact members I2 to I5, inclusive. The two molded sections are mounted upon each other with the Contact members intermediate the top and bottom of the unit as a whole, and in that position both molded sections as a unit, are anchored to the base wall of the box or container 25, within which the switch button controller is to be housed.

The movable contact member I5, that is controlled by the switch operating button i1, serves as a bridging contact between one pair of contact members I2 and I3, or between the other pair of contact members I4 and I5.

As shown in Fig. 7, the switch button I1 is secured to the top or outer end of a slidable `guide plate 21 which moves within a suitable guide passage in the molded sections 23 and 24. A helical biasing compression spring I8 surrounds the guide plate 21 within and underneath the switch button I1 and rests upon or against a shoulder 29 around the guide passage for the guide plate 21.

The guide plate 21 is provided with a central opening 30 of substantially inverted T shape to accommodate the bridging contact Itransversely of the guide plate 21 and to accommodate a helical biasing compressing spring 3I to urge the bridging contact I6 downward. A finger 32 on the guide plate 21 extends into the T shaped opening to locatey one end of the biasing spring 3l against displacement. The other end of the spring 3I is located and held by a lug 33 on the upper side of the bridging contact I6.

In the normal upper or extended position, the switch push-button I1 is moved by its biasing spring I8 to a position at which the bridging contact i6 engages the upper contact members E4 and I5. When the switch button I1 is depressed, the bridging member I6 disengages the contacts I4 and I5 and is moved to engage the stationary contacts I2 and I3. The spring 3| supplies the pressure to hold the bridging Contact I6 against the lower contacts I2 and I3.

The push button I1 is provided with peripheral arc-shaped flange sections 34 which serve the dual purpose of preventing rotation of the pushbutton I1 within the upper molded section 23, and also serving as a stop and detent for the latch I9 when the push-button I1 is moved to its depressed position. An opening 35 is provided in the side walls of the molded section 23 to permit the latch finger ISD to move into position against or over the arc shaped flange section 34.

The latch I9 of molded insulating material is pivotally mounted upon a pin 35 in the frame 2Q. The frame 2@ also supports the second push-button 2I and a control slide bar or plate 31 to control the latch I9.

The frame 2li comprises two side walls 38 and 39 in the form of an inverted U with the lower parts bent out at right angles to serve as feet 4i and 42 to permit the frame to be secured te the base wall of the housing 25. The top portion of the frame is provided with a slot 43 and also has an extension 44 extending downwardly with a portion 45 extending inwardly between the two side walls 38 and 39 to provide a section with a slot 45 to guide the slide plate 31 in its reciprocating motion in response to the push-button 2i and the biasing spring 222.V The slot 4B in the extending portion 45 cooperates with thertop slot 43 to conne the motion of the slide plate 31 to its own plane.

The manner in which the rinterlocking latch operates between the two buttons I1 and 2l may be more readily appreciated upon referring to l Fig. 2. As shown there, the switch push-button I1 is already in its depressed position and is latched in suchV position by the action of the latch finger ISb upon the flange ofl the pushbutton i1. Releasing rotation of the latch I9 is prevented by the pressure of the small boss or back linger ma, on -the back edge of the latch i9, against the side edge of the slide plate 31. Thus the latch I9 may be termed an unstable latch since it cannot of itself act to latch the push button I1, but must be sustained in latching position by slide plate 31 of the push button 2l, to effectively lock push button I1 in the depressed position. The slide plate 31 is provided with a notch 41 in its right hand vertical edge to receive the boss 59a of the latch, when the slide plate 31 is pressed down far enough by the pushbutton 2| to a position where the boss I9a may enter the slot 41 of the slide plate.

When the push-button 2| is depressed to bring the slot 41 adjacent the boss lila, the upward pressure of the push-button I1 on the front latching linger IQb of the latch I3 will tend to rotate the latch I9 counter-clockwise about the pivot pin 3S upon which the latch I9 is pivotally supported. Since the notch 41 is then opposite the boss Illa, the latch I9 may rotate sufciently to move the boss IQa into the notch 41, and that movement is suiiicient for the ringer ISb to'release the ilange 34 on the push-button I1. Pushbutton I1 thereupon moves upward under the pressure of its biasing spring IB and the flange 34 on the push-button l1 is now in position as an edge stop, against the ringer ilb of the latch to prevent clockwise rotation of the latch IS around the pivot pin 36 underthe inliuence of the biasing spring 22 of the latch button 2|.

When the switch button I1 is again depressed, its arc flange 34 moves below and out of the way of the latching iinger portion |919 of the latch I3, and the latch I9 is now free to move in response to the rotating force impressed upon the latch by the biasing spring-22. The latch I9 is thereupon rotated clockwise, out of the notch 41, into the position shown in Fig. 2, where it again moves the nger portion ISb over and above the arc flange 34 to hold the button I1 in depressed position.

The instability of latch I9, previously referred to, is due to the fact that the latch ngers ISa and i322 are offset from the latch pivot 36 at their points of engagement with the respective push buttons, so that the upward force exerted by the compressed spring of whichever push button is depressed, produces a couple on the latch tending to rotate thek latch away from the depressed push button. The latch 'IB-therefore is biased by a depressed push-button-spring to release that push button and to latch the other push button when it is depressed.

The guide plate 31 for button 2l is also provided with a notch 43 in its other edge and is made of proper length and isproperly located to cooperate with the part 49 of the top wall of the frame 20, at the inner edge of slot 43, to determine the two limit positions of the latch button 2 I.

The button ll, when depressed, thus indicates that one circuit is closed, and the lbutton 2| when depressed indicates that the other circuit is closed. For convenience the switch button Il may be colored red and the button 2l green to indicate that the selected circuit is closed or open according to which button is depressed.

The push-button 2l is provided with peripheral :arc shaped Bange sections 28, similar to the ange sections 34, on the push-button l1. It will be noted that both the iiange sections 28 and 34 have portions of their u-pper surfaces at different elevations connected by sloped portions. The particular formation of the upper surfaces of these flanges forms no part of my present invention, land does not cooperate in any way with the push-button structure described and illustrated herein.

An important advantage lies in the fact that the two push-button units have separate `bases or frames I9 and 20 and in the fact that the latch or interlock member i9 is removably connected to push-button l1. This permits the latching or interlocking unit to be supplied separately as an attachment for a standard single push-button unit to convert it into a two-button interlocked push-button station.

My invention is not limited to the speciiic arrangement of the elements as shown nor to the details of construction as illustrated, since they may be variously modied without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim as my invention:

1. A push-button interlock mechanism comprising a push-button, a spring biasing the button to raised position, a contact operable by the button and effective to close one `circuit in the raised position of the button and to close another circuit in the depressed position of the button, an adjacent button assembly including a second push-button, a biasing spring to bias the second button to its raised position, la guide plate for supporting the second button and for guiding the `button movement, a frame supporting the guide plate and embodying guide slot sections for the plate to keep the plate in a predetermined path, a latch pivoted on the frame and embodying a front latching linger to engage the rst button, and a rear pressure lug to serve as Aa latching finger to hold the guide plate in depressed position when the second button is i depressed, the guide plate having a notch in its side edge where engaged by the latch lug, the notch being located where it will be engaged by the latch lug when the button is depressed, to permit the latch to move away from, and release the other push-button.

2. A push-button station comprising two adj acent spring-biased push-buttons, each adapted to occupy va normal raised position and a depressed position, and means for controlling the buttons to permit only one tooccupy a depressed position, said means including a pivoted oscillatable latch disposed between the two buttons, a support for the latch, a guide plate havin-g an edge notch and serving as a support for one button, rand an element on the latch to rit into the notch of the guide plate when the plate and its button are depressed, and a second oppositely disposed element on the latch to engage a portion of the other button when that button is depressed, the

latch then operating to move out of the notch of the guide bar to release that bar and its button to permit the button to move to its raised position, whereupon the guide plate edge :adjacent the notch engages the associated element of the latch and presses against it to hold the latch in effective latching position against the depressed button.

3. A latch unit for a vpush-button switch comprising a unitary frame, a push-button, a spring biasing the button to raised position, a guide bar slidable in the frame and secured at one end to the push-button, and a latch entirely pivotally supported on the frame to engage and latch the slide bar in a Idepressed position of the slide bar and push-button, said latch including a substantially oppositely projecting latching portion for engagement with a push-button switch.

4. A button-operated latch unit for a push- -button switch unit, comprising a supporting frame embodying guide bearing portions, a slide bar disposed to reciprocate in the guide bearing portions and movable to an extended limit position and to a depressed limit position, a pushbutton attached to the outer or upper end of the slide bar, a biasing spring between the frame and the push-button to bias the button away from the frame :and to force the slide bar to its extended position when not otherwise prevented and a latch pivoted on the frameand disposed to latchingly engage the slide bar in the depressed position of the slide bar, said latch including an outwardly projecting latching portion for engagement with a push-button switch, the pivot axis of said latch being spaced inwardly of the latching portions thereof 5. A button-operated latch unit for a pushbutton switch unit, comprising a supporting frame embodying guide bearing portions, a slide bar disposed to reciprocate in the guide bearing portions .and movable to an extended limit position and to a depressed limit position, a long notch in one side edge of the bar stnaddling a portion of the frame which serves as a stop for the end walls of the notch thereby to establish the limit positions of the slide bar, a push-button attached to the outer or upper end of the slide bar, a biasing spring between the frame and the push-button to bias thev button away from the frame land to force the slide bar t0 its extended position when not otherwise prevented, and a latch pivoted on the frame and disposed to latchingly engage the slide bar in the depressed position of the slide bar, and said latch including an outwardly projecting latching portion for cooperation with a push button switch unit.

6. A button-operated latch unit for a pushbutton switch unit, comprising a supporting frame embodying guide vbearing portions, a slide bar disposed to reciprocate in the guide bearing position and movable to an extended limit position Iand to a depressed limit position, a long notch in one side edge of the bar straddling a portion of the frame which serves as a stop for the end walls of the notch thereby to establish the limit positions of the slide bar, and a second notch in the bar and located on the other side edge of the bar to serve as a latching notch for the bar in the depressed position of the bar, a push-button att-ached to the outer or upper end of the slide bar, a biasing spring between the frame and the push-button to bias the button away from the frame and to force the slide bar to its extended position when not otherwise prevented, -a latch `pivoted on the frame and disposed to latchingly engage the slide bar in the depressed lposition of the slide bar, and said latch including an outwardly projecting latching portion for cooperation with a push button switch unit.

7. A button-operated latch unit for a pushbutton switch unit, comprising a supporting frame embodying guide bearing portions, a slide bar disposed to reciprocate in the guide bearing portions and movable to an extended limit position and to a depressed limit position, a long notch in one side edge of the bar straddling a portion of the frame which serves as a stop for the end Walls of the notch thereby to establish the limit positions of the slide bar, and a second notch in the barand located on the other side edge of the bar to serve as a latching notch for the bar in the depressed position of the bar, a push-button attached to the outer or upper end of the slide bar, a biasing spring between the frame and the push-button to bias the button away from the frame and to force the slide bar to its extended position when not otherwise prevented, and a latch pivoted on the frame and disposed to latchingly engage the slide bar in the depressed position of the slide bar, thel latch embodyinga locking finger to enter the latching notch in the bar when the bar is depressed, the finger being disposed to ride on the side edge adjacent the latching notch when the bar is not depressed, and a second locking finger on the opposite edge of the latch for controlling a push-button switch unit according to the position of the latching finger relative to the slide bar. r 8. A button-operated latch unit for a pushbutton switch unit, comprising a supporting frame, embodying guide bearing portions, a slide bar disposed to reciprocate in the guide bearing portions and movable to an extended limit position and to a depressed limit position, a pushbutton attached to the outer or upper end of the slide bar, a biasing spring between the frame and the push-button to bias the button away from the frame and to force the slide bar to its extended position when not otherwise prevented, a latch pivoted on the frame and disposed to latchingly engage the slide ,bar in the depressed position of the slide bar and a latching element on the latch extending outwardly -of said unit for controlling a push-button switch unit according to the position of the latch in latching or in non-latching position relative to the slide bar.

9. A latch unit for a push-button switch comprising a frame, a push button, a spring biasing the button to a raised position relative to said frame, guide means slidable in the frame and secured at one end to the push button, and retaining means movably mounted on said frame to engage and latch said guide means in a depressed position, said retaining means being mounted on said frame for movement away from said guide means upwardly and laterally relative to said guide means and including a projecting supporting portion for engagement with a pushbutton switch.

10. In controlv apparatus, spaced movably mounted control members each resiliently biased to an outer position and including a push button at the outer end thereof so as to be manually operable to an inner position, latch means positioned between said members and mounted for movement toward and away from said members, respectively, each of said members including adjoining side and lateral surfaces with said lateral surface positioned to be engaged by said latch means when its associated member yis at said inner position, Vand said side surfaceY posi-v tioned to engage said latch means when its associated member is at an outer position to maintain said latch means in engagement with the lateral surface on the other of said members, and at least one of said push buttons having a laterally extending flange on whichsaid surfaces of said one member are provided.

11. In control apparatus, spaced movably mounted control members each resiliently biased to an outer position and including a push button at the outer end thereof so as to be manually operable to an inner position, latch means positioned between said members and mounted for movement toward and away from said members, respectively, each of said members including adjoining side and lateral surfaces with rsaid lateral surface positioned to be engaged by said vlatch means when its associated member is at said inner position, and said side surface positioned to engage said latch means when its associated member is at an outer position to maintain said latch means in engagement with the lateral surface on the other of said members, at least one of said push buttons having a Vlaterally extending flange on which said surfaces of said one member are provided, and the other of said members being notched to form the other set of said adjoining surfaces.

12. In control apparatus, spaced movably mounted control members each resiliently biased to an outer position and including a push button at the outer end thereof so as to be manually operable to an inner position and switch contact means adjacent the other end thereof, latch meansy positioned between said members and mounted for movement toward and away from said members, respectively, each of said members including adjoining side and lateral surfaces with said lateral surface positioned to be engaged by said latch means when its associated member is at said inner position, and said side surface positioned to engage said latch means when its associated member is at an outer position to maintain said latch means in engagement with the lateral surface on the other of said members, and at least one of said push buttons being of insulating material and having a laterally extending flange on which said surfaces of said one member are provided.

13. In control apparatus, spaced movably mounted control members each resiliently biased to an outer position and including apush button at the outer end thereof so as to be manually operable to an inner position, latch means positioned between said members and pivotally mounted for movement toward and away from said members, respectively, each of said members including adjoining side and lateral surfaces with said lateral surface positioned to be engaged by said latch means when its associated member is at said inner,J position, and said side surface positioned to engage said latch means when its associated member is at an outer position to maintain said latch means in engagement with the lateral surface on the other of said members, both of said push buttons having inner laterally extending flanges, and said surfaces of Yone of said members being provided on the push button flange of said' one member.

CLARENCE E. GARY. 

